The research component of this project explores how racial-ethnic segregation and inequality shape sexual networks and the spread of sexually transmitted disease (STD). Using data from the National Longitudinal Survey of Adolescent Health (Add Health), I will explore how racial- ethnic segregation and inequality at the school- and neighborhood-levels influence the formation of sexual partnerships. Applying parameter estimates from the Add Health to simulated sexual networks, I will then assess how sexual networks and disease diffusion may progress differently in settings with varying population compositions and patterns of racial-ethnic inequality. Informed by structural sociological theory, this research takes an interdisciplinary approach and applies testable social science hypotheses to problems of infectious disease epidemiology. Through relationships with mentors and advisors, coursework, and participation in professional seminars, the training component of this project would allow me to expand my work on health disparities to include (i) greater attention to social contexts and networks as determinants of health, and (ii) new types of contagious health outcomes. There are three career development objectives for the proposed project: (i) obtain skills and expertise in infectious disease epidemiology and network analysis; (ii) conduct original research on racial-ethnic STD disparities in the U.S.; and (iii) prepare a major grant to support an independent research program in social networks, health disparities, and infectious disease.